Information may often be conveniently indexed using a hierarchical directory structure. It is desirable to make it easy for a user to navigate through the hierarchical directory structure to locate information of interest to the user, and to provide an efficient menu based navigation system.
Alternatively, information may be indexed or arranged using an indexing system or arrangement that defines an information hierarchy. For example, each item of information may be associated with a label or definition, defining its location in the hierarchical structure. The information may comprise data files, and the filenames and/or information stored within the files may define the location of each file in the hierarchical structure. Alternatively, an index that is separate from the files, e.g. in the form of a list, may be provided, in order to define the hierarchical structure.
The defined information hierarchy may be independent from any storage hierarchy of data files or directories on the data storage device(s). Data files may be stored using a non-hierarchical storage arrangement or a storage arrangement that is only partly hierarchical. For example, the data files may all be contained within a single directory on a disk drive or other storage means, or within several directories that have no direct hierarchical relationship, e.g. in different network locations. In this case, an information hierarchy may be set up by providing information defining the hierarchy, e.g. stored within each data file or stored separately. Alternatively, data files may be stored using a hierarchical storage structure. This storage structure may be used to define a hierarchy for navigation of the information, or else a separate independent hierarchy may be defined, e.g. as described above. It is desirable to make it easy for a user to navigate through a hierarchy of information organised in such a way.